Braking apparatus



Jan. 16, 1934.

R. MOORE BRAKING APPARATUS Filed Dec. 11, 1930 2 Sheets-Sheet 1 30500 e[V0019 6y 15,215 $2129 5 Jan. 16, 1934.

R. MOORE 1,944,102

BRAKING APPARATUS Patented Jan. 16, 1934 UNITED STATES PATENT OFFEEBRAKING APPARATUS Roscoe Moore, Kingston, Pa.

Application December 11, 1930 Serial No. 501,624

9 Claims. (01. 188174) engaged in moving cars up the slope the inertiaof the cars will cause a continued travel thereof with the result thatslack is formed in the cable and the cars drop back against this slackafter their motion ceases, thus endangering the cable i and tending tocause breakage thereof. Accordingly, an important object of the presentinvention is the production of a control for the braking apparatus ofsuch hoists of such character that the brakes cannot be applied whilethe hoistdrum is rotating in a direction such that the cars are. beinglifted except when these cars reach their upper travel limit.

I The braking apparatus hereinbefore referred to usually includesweights which actually cause the operation of the brakes. These weightsare in practically all instances held supported by a latch releasedthrough an eleotro-magneti-c means'by limit switches and over-speed orgovernor switches. Obviously, failure of the electric circuit includingsuch switches will permit the elec-tro-magnetic apparatus to act torelease the latch resulting in application of the brakes. Ordinarilysuch weights must be restored to position manually and, accordingly, theelectric circuit fails for any reason during operation of the hoistthere is a tendency on the part of the operator to block up the weightsso that there will be no necessity for. continued manual-effort eachtime that the brakes are applied. This is extremely dangerous in thatthe operator may forget to remove the blocks from the weights when thecircuit is restored thereby rendering the safety brake disastrouslyinoperative. Therefore, a further object of the invention is theprovision of control apparatus for the brake which notonly acts toprevent operation of the brake until the hoist drum is rotating in thedirection permitting the supported cars to lower on the inclined plane,but likewise to prevent operation of the brake even in event of failureof the electro-magnetic circuit until the car has reached its uppertravel limit.

These and other objects I attain by the construction shown in theaccompanying drawings,

wherein for the purpose of .illustration, I have shown a preferredembodiment of my invention, and wherein:

Fig. 1 is a semi-diagrammatic viewshowing braking apparatus constructedin accordance with my invention;

- Fig. 2 is an end elevation of the control mechanism; I

Fig. 3 is aside elevation partially in section thereof;

Fig. 4 is a plan view thereof; and Fig. 5 is a sectional View on line 55of Fig. 3

showing a manner'of mounting the threaded por-' tion of the shaft.

Referring now more particularly to the drawings, the numeral 10generally designates a hoist mechanism including a brake'B and anoperating mechanism 12 for the brake of which no further descriptionneed be given other than to state that it includes a latch 12-a, anelectromagnetic control element 13 controlling operation through thelatch 12--a of a vertically movable bar 14 connected to the brakes B,which bar when released by de-energization of the field of the magneticelement 13 and consequent release of the latch 12a, drops underinfluence of weights 12b instituting operation of the brake B. Suchdevices are ordinarily controlled by a limit switch 15 which may beeither actuated by the cage not shown or in any other suitable or wellknown manner. Limit switch 15 is at present disclosed as opening thecircuit of an operating motor for the hoist and as opening the circuitof the electromagnetic apparatus 13 to permit bar 14 to drop. The bar 14has preferably associated therewith a piston 14-a operating in acylinder l4,-b, communication between the ends of this cylinder beingcontrolled by an adjustable vent 14-0 so that the speed of movement ofthe piston may be regulated. When bar 14 is lowered, it maybe restoredto its normal or brake-releasing position by manipulation of a manuallyoperated reel 12-c.

In the ordinary apparatus in case of accidental opening of switch 15, orany other operation which tends to open the circuit of both the motorand the electromagnetic apparatus, or the electromagnetic apparatusalone, the operation of the apparatus 12 is immediate. It will beobvious that in the ordinary apparatus of this character a suddenapplication of the brake would result, and if the cage or car is at thetime of application of-the brake moving upwardly, there would be atendency of the car to continue its movement forming cable slack andcausing the dangerous condition hereinbefore referred to.

In accordance with my invention, I arrange beneath the bar 14 a suitablesupport 18 mounting bearings 19 and 20, one of which is formed as a nut,as more clearly shown in Fig. 5. Mounted in the bearings 19 and 20 is ashaft 21 formed with threaded and plain sections 22 and 23. The plainsection has splined thereto a sprocket 24 received in a furcation ofbearing 20. The threaded section 22 operates through the nut of bearing19, and has an extended end 25 to which is adjustably secured a drum 26underlying rod 14. The lower end of rod 14 has hingedly connectedthereto at 27 a foot 28, the under surface of which in the normalposition of the bar closely overlies the surface of drum 26 in slightlyspaced relation thereto. The foot 28 at its pivotal connection hasshouldered engagement at 29 with bar 14 preventing swinging movement ofthe foot in one direction so that this foot when lowered upon drum 26will, if the rotation is in one direction, remain rigid with relation torod 14, and if the rotation is in the opposite directon, be kicked outby the drum so that it will not serve as a support for rod 14 but willpermit this rod to fall. Sprocket 24 is suitably connected with thehoist mechanism as at 30 so that the shaft 21 is rotated when thehoisting mechanism is in operation. In the present diagrammaticillustration of Fig. 1, the connections are shown as direct, but itwill, of course, be understood that these connections will be of suchcharacter that the shaft 21 will be given a desired speed with relationto the speed of the drum and will be rotated in the proper directionwhen the drum is in use in elevating the cage. During operation of thehoist the drum 26 is simultaneously rotated and longitudinally moved,the direction of rotation and longitudinal movement, of course,depending upon the direction of movement of the hoist. When the hoist isbeing lowered, the direction of rotation is such that the foot 28 willbe kicked out by the drum and the foot rendered inoperative to preventdownward movement of the member 14 to an extent causing operation of thebrakes. Application of the brakes will not occur at this time, however,unless the circuit is opened for the solenoid 13 is energized at allpther times and will not permit the member 14 to drop. When the hoist isbeing raised, the rotation is such that the foot 28 is not kicked out bythe drum but is held in alignment with the member 14. The drum, however,due to its longitudinal travel is, when the hoist engages the limitswitch, withdrawn from beneath the end of the foot 28 so that the member14 may drop sufiiciently to cause operation of the brakes. It will, ofcourse, be obvious that it is unnecessary that the drum travelsufficiently far to free the foot of the drum during the loweringmovement and at the time that the lower limit switch is engaged, for thereason that the brakes are effective at any time that the circuit isopened during such lowering movement.

The operation of this apparatus is as follows: Assuming the hoist to beengaged in elevating the cage, if at any time prior to the operation ofthe limit switch 15, the circuit of electromagnetic apparatus 13 isbroken, as for example, by manual switch 31, bar 14 will drop. Drum 26will, however, check the downward fall of this bar and as a result latch12a will not be disturbed and brake B will not be applied and as long asthe hoist continues to rise, the foot 28 will remain rigid with relationto bar' 14 and will prevent dropping of the bar a distance sufiicient tocause the brake B to operate. When, however, hoisting ceases and thecage starts to drop back, movement of the drum 26 is immediatelyreversed with the result that the foot 28 is kicked to its dotted lineposition in Fig. 2, permitting bar 14 to fall and the brake to beapplied. Assuming that the interruption of the circuit ofelectromagnetic apparatus 13 does not occur until the cage oper ateslimit switch 15, then the drum 26 through operation of the screw thread22 through the nut of bearing 19 will have shifted to the right in Fig.3 a distance such that the foot 28 will no longer lie thereover, butwill be positioned as shown in dotted lines in Fig. 3.

It will also be obvious that the construction employed is capable of acertain range of change and modification without in any manner departingfrom the spirit of my invention, I, accordingly, do not wish to beunderstood as limiting myself to the specific arrangement hereinbeforeset forth except as hereinafter claimed.

I claim:

1. In combination with an apparatus having two operating phases, acontrol therefor including a member effective when moved to apredetermined extent, a stop for the member normally preventing movementthereof to such extent and means increasing the efiective distancebetween the member and stop during one operating phase of the apparatus.

2.'In combination with an apparatus having two operating phases, acontrol therefor including a member efiective when moved to apredetermined extent, a rotatable drum arranged in the path of themember, an interponent carried by the member and engaging the drum uponmovement of the member through a distance insufiicient to render iteffective, said interponent being pivoted to the member to swing in aplane transverse to the axis of the drum and having engagement with themember limiting such pivotal movement under the influence of forceapplied in one direction of rotation of the drum. 7

3. In combination with an apparatus having two operating phases, acontrol therefor including a member effective when moved to apredetermined extent, a rotatable drum arranged in the path of themember, an interponent carried by the member and engaging the drum uponmovement of the member through a distance insufficient to render iteffective, said interponent being pivoted to the member to swing in aplane 180 transverse to the axis of the drum and having engagement withthe member limiting such pivotal movement under the influence of forceapplied in one direction of rotation of the drum, and means'for shiftingthe drum longitudinally as it is rotated.

4. In control apparatus of the character described, alongitudinally-movable bar having a foot pivoted thereto to swing in apredetermined plane, means limiting pivotal movement of the foot in onedirection and while the foot is aligned with the bar, and a drumarranged in the path of the bar and in close proximity to the free endof the foot and means for rotating said drum in either direction.

5. In control apparatus of the character described, alongitudinally-movable bar having a foot pivoted thereto to swing in apredetermined plane, means limiting pivotal movement of the foot in onedirection and while the foot is aligned 350 with the bar, and a drumarranged in the path of the bar and in close proximity to the free endof the foot and means for rotating said drum in either direction, andfor shifting the drum longitudinally.

6. In combination with an apparatus having two operating phases, acontrol therefor including a member eifective when moved to apredetermined extent, a stop for the member normally preventing movementthereof to such extent, means increasing the effective distance betweenthe member and stop during one operating phase of the apparatus, andmeans for withdrawing the stop from the path of the member after apredetermined duration of the other operating phase of the apparatus.

7. In combination with a reversely operable hoist, a brake for thehoist, an actuator for the brake including a longitudinally shiftablemember, a drum arranged in the path of the longitudinally shiftablemember and operated from the hoist and a foot for the longitudinallyshiftable member rigid thereto against forces applied to the foot byrotation of said drum in one direction and pivoted with relation theretounder the influence of forces applied by rotation of the drum in theopposite direction while the foot is engaged therewith, said footengaging said drum prior to movement of the longitudinally shiftablemember through a distance rendering the brake efiective.

8. In combination with a reversely operable hoist, a brake for thehoist, an actuator for the brake including a longitudinally shiftablememher, a drum arranged in the path of the longitudinally shiftablemember and operated from the hoist a foot for the longitudinallyshiftable member rigid thereto against forces applied to the foot byrotation of said drum in one direction and pivoted with relation theretounder the influence of forces applied by rotation of the drum in theopposite direction while the foot is engaged therewith, said footengaging said drum prior to movement of the longitudinally shiftablemember through a distance rendering the brake effective, and means forshifting the drum longitudinally as it is rotated.

9. The combination with a member to be raised and lowered of a hoist forraising the same, means to limit the raising operation of the hoist, anormally inoperative brake for the hoist, an actuator for said brake,means effective only during operation of the hoist to raise the memberfor rendering the brake-actuator inoperative, and means to render thelast-named means inoperative when the limit means is operated.

ROSCOE MOORE.

